flattens Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition verb. to make something flat or level. Example Sentence Sarah uses an iron to flatten her clothes and remove any wrinkles before wearing them. More Example Sentences He flattens the paper before drawing. Synonyms smooths; levels; compresses Antonyms bumps; raises; bulges Hear It! Say It! Write It! flattens Switch to cursive Start Share with your friends: